As an example of the conventional stringed instrument having a tailpiece such as violin, viola, cello and contrabass, the basic structure of a violin will be described. As shown in FIG. 14, the violin 100 includes a hollow box-shaped body 110, neck 120 provided on a front end of the body 110, strings 130, tailpiece 140 to which ends of strings 130 are fastened, and bridge 150 for transmitting the vibration of the strings 130 to the body 110.
The body 110 includes an upper plate 112, lower plate 114 and side plate 116 for connecting the upper plate 112 and lower plate 114 so as to form a hollow resonance body.
The strings 130 may be individually tensioned on the upper plate of the body with predetermined intervals therebetween. Observed from the back end portion to the front end portion of the body, four strings, from the right to left, e-string 130e, a-string 130e, d-string 130e and g-string 130e are provided in this order. The basic frequency of the released e-string 130e is the highest and the basic frequency of the released strings decreases in the order of a-string 130a, d-string 130e and g-sting 130g. The front ends of the strings 130 are wound to the pegs 122 provided in the front end of the neck and the back ends of the strings are fastened to the tailpiece 140.
In the front end portion of the tailpiece 140, four string holes 142e, 142a, 142d, 142g are defined. The back ends of e-string 130e, a-string 130a, d-string 130d and g-string 130g are inserted in and fastened to the string holes 142e, 142a, 142d, 142g, respectively.
As shown in FIG. 15, in a backward portion of the tailpiece 140, two tail gut insertion holes 144 are formed. The ends of tail gut 150 are inserted in the tail gut insertion holes 144 from a back end direction. In the ends of tail guts 150 drawn forward through the tail gut insertion holes 144, a knot 152 is formed so that the tail gut 150 is fastened to the tailpiece 140. As shown in FIG. 14, a u-shaped portion of the tail gut 150 which protrudes from the back end of the tailpiece 140 is connected to an end pin 118 so that the tailpiece 140 is fastened to the body 110 and the strings 130 are provided on the upper plate 112 of the body 110 with specific string tensions.
On the surface of the upper plate 112 of the body 110, a bridge 150 is positioned between the neck 120 and the tailpiece 140 for supporting the four strings 130 and transmitting the vibration of the strings 130 to the body 110. The load applied to the bridge 150 from the e-string is the largest and the loads applied to the bridge 150 from the strings decreases in the order of a-string 130a, d-string 130d and g-string 130g. 
The violin having the above structure generates tones by the vibration of the four strings when drawn by a bow or plucked by fingers, and resonance of the body is caused by the vibration transmitted to the body 110 via the bridge